1. Field of the Invention
This invention concerns toothbrushes, and more particularly relates to a toothbrush having a set of bristles for cleaning the teeth and a second set of bristles for cleaning the spaces between the teeth, and under the gumline.
2. Description of the Prior Art
The fundamental purpose of toothbrushes is to remove plaque and debris from the tooth surfaces, both along their outer surfaces and in the interproximal areas as well as provide gum and interdental stimulation. There is a continuing need to improve the interproximal cleaning effectiveness of toothbrushes, particularly because many consumers do not floss.
Currently marketed toothbrushes are classified into three categories: soft, medium and firm according to the degree of hardness or stiffness of the bristles. Firm toothbrushes, having stiff bristles, clean plaque well but irritate the gums. Soft toothbrushes are unable to provide adequate cleaning in the interproximal areas between the teeth. Medium toothbrushes cannot meet all three needs because some teeth need harder cleaning, others need minor cleaning, while the gums need just a massaging.
U.S. Pat. No. 6,021,541 to Mori et. al. describes a toothbrush intended to provide improved cleaning of interdental regions, and comprised of sheath/core bristles wherein the sheath is made from a polyester resin and the core is made from a polyamide resin. Bristles having tapered distal tip extremities are also disclosed.
U.S. Pat. No. 5,732,433 to Gocking et. al. discloses an interproximal brush for an electric toothbrush. The brush has bristles of two different heights, the longer length bristles providing interproximal cleaning function.
U.S. Pat. No. 5,398,367 to Lu concerns a toothbrush having both soft and hard bristles. The soft bristles are longer than the hard bristles, and provide a gum massaging effect. The variation in hardness of the bristles is accomplished by varying the diameter of the bristles.
U.S. Pat. No. 5,392,483 to Henizelman et. al. discloses a toothbrush for improved cleaning, gum stimulation and mouth feel, having varying bristle tuft heights, angling of the tufts, and critical positional arrangement of the tufts.
U.S. Pat. No. 5,511,275 to Volpenhein et. al. describes a toothbrush for achieving improved interproximal cleaning without increasing gum irritation. The ends of the bristles are rounded and have a critically selected stiffness.
U.S. Pat. No. 5,535,474 to Salazar concerns a toothbrush for cleaning teeth while simulating the gums, said toothbrush having polishing rods and stimulator rods that extend above surrounding bristles.
U.S. Pat. No. 5,926,897 to Volpenhein discloses a toothbrush for interdental stimulation comprised of a plurality of tufts having a multiplicity of primary and secondary bristles, said secondary bristles being stiffer than said primary bristles and extending above said primary bristles.
However, despite considerable prior effort, there still exists a need for a toothbrush having the ability to clean the teeth while providing the benefits of flossing. Some of the aforesaid prior toothbrushes, although having technical merit, would be expensive to manufacture.
It is accordingly a primary object of the present invention to provide a toothbrush which serves well in cleaning teeth and also provides the benefits of flossing.
It is another object of this invention to provide a toothbrush as in the foregoing object which will not irritate the gums.
It is a further object of the present invention to provide a toothbrush of the aforesaid nature which is easy to manipulate during the brushing activity.
It is a still further object of this invention to provide a toothbrush of the aforesaid nature of durable construction and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.
The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a toothbrush comprising an elongated resilient handle extending between two ends and a brush head disposed at one of said ends, said brush head having a flat support surface and a plurality of tufts of bristles fabricated of polybutylene terephthalate, each tuft comprised of:
a) a multiplicity of primary bristles of uniform cross-sectional configuration having proximal ends embedded in said head and distal ends extending orthogonally outward from said support surface, and
b) a multiplicity of secondary bristles having proximal extremities embedded in said head and pointed distal extremities extending orthogonally outward from said support surface to an action zone beyond the distal ends of said primary bristles, said secondary bristles having a tapered cross-sectional configuration in said action zone that terminates in said pointed distal extremity.